In the vast world of new materials, fumed silica is like a low-key "hidden champion". Although it is rarely known to the public, it plays an irreplaceable role in many key fields.
Fumed silica, also known as fumed white carbon black, is a high-tech ultra-fine inorganic new material. Its particle size is extremely small, which creates a large specific surface area, giving it strong surface adsorption and high surface energy. At the same time, it has high chemical purity and good dispersion performance. It shows unique properties in thermal resistance and electrical resistance. It is also porous, non-toxic, odorless, pollution-free and resistant to high temperatures.
The preparation of this magical material usually adopts chemical vapor deposition (CVD), also known as pyrolysis, dry method or combustion method. Silicon tetrachloride, oxygen (or air) and hydrogen are used as raw materials, and react under high temperature: SiCl₄ + 2H₂ + O₂→SiO₂ + 4HCl. The whole process involves a series of delicate steps such as raw material pretreatment, gasification, gas phase hydrolysis, particle aggregation, collection and subsequent treatment, and finally obtains a gas phase silica product with excellent performance.
With its unique performance, gas phase silica has been widely used in many industries. In the rubber field, adding a small amount of gas phase silica can significantly improve the strength, wear resistance and aging resistance of rubber products, so that the performance of ordinary rubber can leap to the level of high-end rubber products. In the plastic industry, it can make plastics denser. For example, after adding it to polystyrene plastic film, the transparency, strength, toughness, waterproof and aging resistance of the film are greatly improved. In coatings and inks, gas phase silica plays a thickening and thixotropic effect, improves rheological properties, prevents pigments and fillers from settling and stratification, and improves product weather resistance and scratch resistance. In addition, it is also widely used in cosmetics, sealants, medicine, optical coatings and other fields, providing a solid material foundation and technical guarantee for the development of related industries. In this way, although gas phase silica is "invisible", it has a profound impact on and promotes the progress and innovation of the new material field and even many industries.